There is a rapidly growing trend toward mobile and remote data access over high-speed communication networks, such as provided by 3G or 4G cellular services. For example, using these services, users now rely on their smartphones for texting, access to email, banking, and social media, and for sending and receiving pictures and video.
Typically, wireless network performance depends in part on the quality of the transmission channel. For example, if the channel conditions are good, the network may perform with higher speed and capacity than when the channel conditions are poor. To obtain the best network performance, wireless networks may rely on user devices (e.g., user equipment “UE”) to report control information back to the network. The control information includes parameters indicating the channel conditions and/or transmission parameters. One mechanism available to user devices to report control information back to the network is through a dedicated physical uplink control channel (PUCCH). The network receives the control information over this channel and uses the received parameters to adjust data transmissions for optimum performance based on the network conditions indicated by the received parameters.
The PUCCH carries important control information, including Channel Quality Indicator (CQI) and Hybrid Automatic Repeat Request Acknowledge (HARQ-ACK) information. The PUCCH may be formatted in several ways to communicate the control information, such as format 1, format 2x (format 2, 2a, 2b) and formats 3, 4, 5, etc. These formats identify how the control information is encoded and/or modulated in the PUCCH.
The performance of ACK messages play an important role in the overall downlink performance as the residual error rate of HARQ is in the same order of the feedback error rate of the ACK bits. The CQI information represents the recommended modulation scheme and coding rate to be used for downlink transmissions. Its accuracy greatly impacts the overall system throughput that can be achieved in a noisy channel. Thus, improving the error performance of both CQI and ACK detection is desirable to the achieve improved network throughput
Therefore, it is desirable to have a detection mechanism that efficiently detects with high probability, control bit information transmitted from a UE over a PUCCH.